The present invention relates to the field of computer security and more particularly to techniques for controlling access to resources in a multi-domain distributed computing environment.
Advances in communication network technologies coupled with the explosive growth in the usage of computer systems have significantly increased the number of resources available to users via communication networks. Due to the rising popularity of such communication networks, an increasing number of enterprises are replacing their legacy centralized information processing models with distributed systems comprising a plurality of computer systems interconnected via a communication network, such as the Internet. The use of such distributed systems has allowed enterprises to transcend geographical boundaries and share resources between a multitude of users irrespective of the physical location of the users. For example, an enterprise having offices in Seattle, Denver, and San Francisco may have a distributed computer network which allows users in any of the three offices to access resources deployed at the other office locations. Distributed computer networks allow efficient sharing of resources among users of the distributed system in a seamless manner. Examples of resources that may be shared include information resources such as databases, files, etc., or operational resources such as devices or processes.
The increased deployment of resources via distributed networks has led to a heightened awareness of security concerns regarding the need to protect the resources from unauthorized access. Several security models have been developed to control access to resources. These models typically include a “principal” who requests an operation to be performed on a particular resource, and an “access controller” who receives the request from the principal and based on the request determines if the requesting principal is authorized to perform the requested operation on the resource. Access rights for a resource are generally defined by access rules associated with the resource. The access rules indicate the principals and the operations which may be performed on the resource. The requesting principal is allowed to perform the requested operation on the requested resource if authorized by the access rule.
Several access control systems have been developed based on the security model described above which use mechanisms such as user groups, access lists, capability lists, and lock-key mechanisms to regulate access rights to resources. With the ever-increasing use of distributed systems, the success or failure of such systems in a distributed environment is typically measured by the system's ease of use, the access control granularity offered by the system, and the scalability of the system with respect to the number of users, resources, operations to be performed on the resources, and the number of requests. While many of the conventional systems listed above are well suited for centralized processing models, they do not always fare as well when used in a distributed environment. In particular, these conventional access control systems do not provide the desired ease of use, access control granularity, and scalability in a distributed environment. As a result, many of these systems are difficult to use and administer and do not scale well as the number of resources, requests, and users increases.
Thus, there is a need for an access control system which can efficiently control access to resources in a distributed environment. It is desired that the system be easy to use and administer, provide fine grained access control granularity, and be easily scalable as the number of principals and resources increases.